Case Report

Introduction: The concept of Neuromyelitis Optica (NMO) spectrum disorders (NMOSD) encompasses patients with or without NMO-Immunoglobulin G antibodies, fulfilling several clinical and imagiological criteria defined in the international consensus diagnostic criteria of 2015. The coexistence of other autoimmune disorders is common and considered supportive of NMOSD" diagnosis.

Case Report: A 24 year-old female was admitted due to a sudden painful hypovision in the left eye. The etiological investigation was negative but brain MRI showed T2 hyperintensity of the left optic nerve with gadolinium enhancement, but no signal changes in the brain parenchyma. Eleven years before, she had been diagnosed with autoimmune thyroiditis based on hypothyroid goiter with biopsy-proven chronic lymphocytic inflammation and positive thyroid-related antibodies. Two years after optical neuritis, she developed sensory complaints below a thoracic defined level. MRI revealed a diffuse T2 hyperintense area from D2 to D5. She tested positive for antibody anti-NMO/Aquaporin-4. One month later she had a new episode of left optic neuritis. With two optic neuritis and one longitudinally extensive myelitis, with positive serum test for NMO antibody, she was diagnosed with NMOSD with hypothyroidism and started Azathioprine.

Discussion: In up to 20-30% patients with NMOSD there is an association with autoimmune thyroiditis. In the literature the reference to “thyroid disease” and seroprevalence of thyroid-related antibodies in NMOSD patients, ranges between 5.6% and 20.5%, but case reports/series with definite clinical, analytical and histological characterization of the thyroiditis are scarce. We present a case of a patient with clear data consistent with autoimmune thyroiditis who, more than a decade later, was diagnosed with NMO